Why The Immunity Band Is Actually Worth The Effort
Most people ignore the Immunity Band until they're deep in the mines and suddenly poisoned for the fourth time in an hour. By then, you've already spent two hours on a floor and your health is half gone. The band itself is simple: it prevents the poisoned status effect entirely. That's it. But the difference between clearing the 80th floor of the mines without worrying about black slimes and dying because you misjudged one hop is significant. I used to run boots only. Slime Boots for the jumping, nothing else. Thought I didn't need the extra slot. Then I hit Floor 80 and the black slimes started stacking up. Each application of poison was dealing 14 damage over time, and with the mountain goats spawning nearby, I'd get poisoned three times in a single run. My health would drain before I even reached the bottom of the floor. Lost about an hour of progress one evening just because I wouldn't make the item. The fix took me twenty minutes at my first workstation and solved the entire problem.
Your Guide To Getting The Immunity Band Essential Strategies For Farm Safety
There are three reliable ways to obtain one. The first and cheapest is buying it from the Adventurer's Guild for 1500g. Robin sells the crafting recipe there once you've unlocked the guild, and it uses one iron bar and one coal. You'll find iron ore throughout the mines starting around floor 10, and coal from cooking or purchasing it from Pierre. The actual crafting takes a few seconds at any carpentry bench. The second way is finding it as a drop. Black slimes have a roughly 5 percent chance to drop the Immunity Band when killed on floors 80 through 100. This is RNG-dependent and you could kill twenty black slimes and get nothing, or get one on your first try. I got mine from a black slime on my third attempt at Floor 85, so don't expect it to happen immediately. The drop rate doesn't scale with difficulty or playstyle, which surprises a lot of people. The third option is the Traveling Cart. It appears on Fridays and Sundays outside your farm gate, and the Immunity Band cycles in and out of its inventory. There's no way to influence what it carries. I've checked the cart every trip for twelve in-game weeks before I finally saw it. If you're impatient, just craft it from the guild recipe instead of chasing the cart.
Once you have it, equip it in any accessory slot. The band doesn't stack with other immunity gear because there isn't really other immunity gear. The Warrior Ring gives attack speed and damage but doesn't prevent poison. The same goes for the Lava Charm or any other mine-focused accessory. If you're running full accessory slots and still hitting walls, you're probably carrying three combat rings and forgetting this one entirely. I made that mistake for longer than I want to admit. Here's something most guides don't mention: the Immunity Band does not protect you from the Dragoon or the Shadow Shaman's poison projectile in the Skull Cavern. It blocks the poison status effect from slimes and standard mine monsters, but certain boss-level enemies have their own separate damage mechanics. In the regular mines, floors 1-79 have zero poisoned enemies, so the band is useless up to floor 80. Floor 80 and above is where black slimes and poison frogs appear. That's the actual threshold where the band becomes relevant. Another thing people overlook: the band prevents the debuff, not the source. A poisoned black slime is still a black slime. It will still hit you for normal damage and still spawn a swarm if you're not careful. The band just means you don't have to manage the DOT on top of managing the fight. This matters because when you're poisoned, your health tick-down feels random and panic-leading. Remove that variable and you play more cleanly.
Get the Full Details

There are some edge cases worth knowing. If you're doing the Dragonfood quest and need to collect slime eggs, the immunity band won't stop slimes from attacking you. They still attack. They just don't apply poison. Also, if you craft a second Immunity Band, you can give it to someone as a gift. It's a ten-heart gift for spouses and some of the later villagers, though the utility is wasted if they don't go mining. The band is equippable by your spouse but they won't use it actively while farming, so gifting it is mostly a decorative choice. The real bottleneck isn't obtaining the band. It's managing your inventory while carrying it. The accessory slots fill up fast if you're mining regularly. I recommend running the band plus Lava Charm plus either the Slime Hutch ring or the Spikeweed ring depending on whether you need jumping or defense. Anything beyond that and you're cutting into combat effectiveness for marginal gains. If you find the mines too dangerous before getting the band, you can always use the elevator in the Skull Cavern to skip ahead, but that doesn't help with poison until floor 80 anyway since the regular mine is where poison starts. There's no shortcut around floor 80 in the standard mine. You have to reach it. The elevator is a separate system and doesn't let you bypass the progression gates.
For anyone building a character focused on combat and exploration, the Immunity Band should be one of the first accessories you prioritize after your weapons are settled. It costs about two iron bars and a handful of coal, which you collect naturally while mining. The time investment to craft it is less than what you lose to poison in a single bad floor run. I'd say that's worth it.